1. Field of the Invention
The present invention relates to an equalizer, in particular, to a technique for adjusting a waveform equalization coefficient of a decision feedback equalizer.
2. Description of the Related Art
There are many types of equalizers. Among them, there is a decision feedback equalizer (DFE). The decision feedback equalizer is known as one of waveform equalization techniques for compensating transmission loss. In the decision feedback equalizer, adjustment of the waveform equalization coefficient is performed to compensate the transmission loss. As techniques related to the adjustment of the waveform equalization coefficient, for example, techniques described in IEEE Transactions on Communications, Vol. COM-29, No. 11, November 1981 and JP-2011-151765-A are known.
IEEE Transactions on Communications, Vol. COM-29, No. 11, November 1981 describes a technique that adaptively adjusts a filter response by selecting a corresponding filter response from a table in a memory when receiving a transmission signal and performing feedback so as to subtract an output of the selected filter response from a reception signal. JP-2011-151765-A describes a technique that performs filtering so as to equalize the number of occurrences of each bit pattern which a bit string can form.